Method of manufacturing a super high floating line

ABSTRACT

Methods of manufacturing fly fishing lines with very low specific gravities entail adding polymer microspheres to a base coating and coating a core with the base coating containing the added polymer microspheres. To manufacture fly lines having multiple coatings, a second coating, which may contain polymer or glass microspheres, is disposed around a first coating that contains polymer microspheres.

RELATED APPLICATION

This application is a division of U.S. patent application Ser. No.11/213,588, filed Aug. 26, 2005, now U.S. Pat. No. 7,406,797, whichclaims the benefit of U.S. Provisional Application Ser. No. 60/608,453,filed Sep. 9, 2004. The disclosure of U.S. Provisional Application Ser.No. 60/608,453 is incorporated herein by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates to a super high floating line for use in flyfishing and related activities, as well as a method of manufacturing asuper high floating line.

2. Description of the Related Art

Generally, it is greatly desirable to utilize a line while fly fishingthat has a relatively low specific gravity. The lower the specificgravity, the higher the line floats since less water is displaced.Currently available fly fishing lines have specific gravities in therange of 0.85 to 0.95. Various fly fishing lines have coatings thattypically are comprised of polyvinyl chloride polymer or urethane thatinclude respectively glass microspheres or gaseous filled cells,dispersed throughout the coating to impart floatability by reducing thespecific gravity to less than 1.00, usually somewhere between 0.85 and0.90. Currently, the glass microspheres utilized within the lines, suchas Minnesota Mining and Manufacturing Company's G18/500 Microspheres, aswell as chemical blowing agents that produce gas filled cells, do notprovide for the manufacture of fly fishing lines with specific gravitiesless than 0.80.

Today, the fly fishing angler continues to seek fly fishing lines thatfloat higher, have a lower specific gravity, are more durable, are moresupple and perform better than currently available lines. As is wellknown, a fly fishing line that features a very low specific gravityfloats higher on the surface of the water thus allowing the angler topick the fly line up off the water with greater ease. When the tip ofthe fly fishing line sinks, initiating a cast is difficult since greaterenergy must be applied to the line throughout the rod in order to removethe line from the water. A low specific gravity thus allows the fly lineto float higher on the surface of the water thereby decreasing surfacetension and friction off the water when initiating a cast. Additionally,a fly fishing line with a high floating tip reduces the occurrence ofthe butt of a nylon leader attached to the high floating tip of the flyline from sinking. When the leader butt sinks, it submerges the tip ofthe fly fishing line making initiating the cast more difficult due tothe increased friction created by the leader being pulled up through thewater column. Furthermore, the tip of a high floating line is easier tosee thus making it easier for the angler to detect a fish taking the flywhen fishing subsurface flies.

In addition, it is desirable to provide a fly fishing line that is moresupple, has less memory and is resistant to coiling in cold weather andin typical water conditions. The coils of a stiff line can penetrate thesurface and be pulled down into the water column water negativelyaffecting the floatation of the line.

Improvements to fly fishing lines continue. Various examples includethose described in U.S. Pat. No. 3,868,785; U.S. Pat. No. 5,207,732;U.S. Pat. No. 5,296,292; U.S. Pat. No. 5,437,900; U.S. Pat. No.5,625,976; U.S. Pat. No. 6,167,650; and U.S. Pat. No. 6,321,483, thedisclosures of which are hereby incorporated herein by reference.However, further improvements are desired.

OBJECTS AND SUMMARY OF THE INVENTION

Therefore, it is an object of the present invention to provide a flyfishing line with a specific gravity lower than currently availabledesigns.

It is another object of the present invention to provide a fly fishingline with a lower specific gravity that is also more durable, moresupple and has less memory than currently available designs.

In accordance with the present invention, a fly fishing line iscomprised of a core, and a coating having a plurality of polymermicrospheres disposed around the core.

As an aspect of the present invention, the fishing line has a specificgravity lower than 0.85. In other variations, the fishing line has aspecific gravity lower than 0.8.

As another aspect of the present invention, the fishing line includes afloating tip having a specific gravity lower than 0.7.

As a further aspect of the present invention, the concentration ofmicrospheres within the coating is between 1 and 10% by weight.

As an additional aspect of the present invention, the coating is a PVCplastisol, and the amount of polymer microspheres in the coating is lessthan 5% by weight.

As yet another aspect of the present invention, the coating has aspecific gravity of substantially equal to or less than 0.8 and aviscosity of under 100,000 centistokes at 2.5 RPM.

In accordance with another embodiment of the present invention, afishing line comprises a core, a first coating having a plurality ofpolymer microspheres disposed around the core, and a second coatingdisposed around the first coating.

As an aspect of this embodiment, the second coating has a plurality ofmicrospheres of a preselected material.

As another aspect of this embodiment, the microspheres in the secondcoating are different from the microspheres in the first coating.

As a further aspect of this embodiment, the second coating has aplurality of glass microspheres.

As an additional aspect of this embodiment, the second coating has aplurality of polymer microspheres, and viscosities of the first andsecond coatings are substantially different.

As yet another aspect of this embodiment, the first and second coatingscontain a fused interface.

As yet a further aspect of this embodiment, the first coating isdisposed around first and second portions of the core, the secondcoating is disposed around that portion of the first coating disposedaround the first core portion, and the fishing line includes a thirdcoating disposed around that portion of the first coating disposedaround the second core portion, wherein the second and third coatingsare different.

As a feature of this aspect, the second coating includes polymermicrospheres, and the third coating includes glass microspheres.

As yet an additional aspect of this embodiment, a running line portionof the fishing line has a diameter of substantially between 0.035 and0.045 inches and a specific gravity of less than 0.85.

As still yet another aspect of this embodiment, a floating tip portionof the fishing line has a diameter of substantially equal to or lessthan 0.045 inches and a specific gravity of less than 0.7.

As still yet a further aspect of this embodiment, a body portion of thefishing line has a diameter of substantially between 0.045 and 0.115inches and a specific gravity of less than 0.85.

As still yet an additional aspect of this embodiment, the fishing linehas a slickness corresponding to, as measured using a tensile testerwith a 10 kilogram load cell, less than 0.3 pounds of force required topull a 0.05 inch diameter fishing line having a 0.123 pound attachedweight over a 7 inch diameter chrome plate wheel at a rate of 10 inchesper minute, the line having a surface contact length of 22 inches to thewheel.

In accordance with a further embodiment of the present invention, amethod of manufacturing a fishing line includes adding polymermicrospheres to a base coating, and coating a core with the base coatingcontaining the added polymer microspheres.

Aspects and features of this embodiment are similar to various aspectsand features mentioned above

In accordance with an additional embodiment of the present invention, amethod of manufacturing a fishing line includes providing a core,disposing a first coating having a plurality of polymer microspheresaround the core, and disposing a second coating around the firstcoating.

As an aspect of this embodiment, the two disposing steps are carried outto provide a fused interface between the first and second coatings.

As another aspect of this embodiment, the first coating disposed aroundthe core is partially cured so that the second coating is disposedaround a partially cured first coating.

As another aspect of this embodiment, the shape of the partially curedfirst coating is sufficiently maintained while the second coating isdisposed over the first coating.

Other aspects and features of this embodiment are similar to variousaspects and features mentioned above.

Various other objects, advantages and features of the present inventionwill become readily apparent to those of ordinary skill in the art, andthe novel features will be particularly pointed out in the appendedclaims.

BRIEF DESCRIPTION OF THE DRAWINGS

The following detailed description, given by way of example and notintended to limit the present invention solely thereto, will best beappreciated in conjunction with the accompanying drawings, wherein likereference numerals denote like elements and parts, in which:

FIG. 1 is a schematic illustration of a fly line in accordance with afirst embodiment of the present invention;

FIG. 2 is another schematic illustration of a fly line manufactured inaccordance with the first embodiment;

FIG. 3 is a schematic illustration of a fly line in accordance with asecond embodiment of the present invention.

FIG. 4 is a schematic illustration showing a cross-sectional view of thefly line shown in FIG. 3;

FIG. 5 is a diagram useful in explaining the process of manufacturing atwo coat line in accordance with the present invention;

FIG. 6 is a photograph, with 50× magnification, of a longitudinal crosssection of the fly line manufactured by the process described withreference to FIG. 5;

FIG. 7 is a schematic illustration of a fly line in accordance with athird embodiment of the present invention;

FIG. 8 is a schematic illustration showing a cross-sectional view of thefly line shown in FIG. 7;

FIG. 9 is a schematic illustration showing an exemplary fly line inaccordance with a fourth embodiment of the present invention;

FIG. 10 is a diagram illustrating the slickness of a single coat line;and

FIG. 11 is a diagram illustrating the slickness of a double coat line.

DETAILED DESCRIPTION OF CERTAIN PREFERRED EMBODIMENTS OF THE INVENTION

In accordance with the present invention, a super high floating flyfishing line (also called, for convenience, “fly line” or “line” herein)is comprised of a core and one or more coatings disposed over the core,and preferably has a specific gravity of less than 0.85 or 0.80, asdescribed below.

Referring to the drawings and particularly to FIG. 1 thereof, a fly linein accordance with a first embodiment of the invention is schematicallyshown. As shown, fly line 10 is comprised of an inner core 12 and anouter coating 14 disposed over the core. Core 12 is made of one or morefilaments, such as a nylon monofilament or a nylon braidedmultifilament, which are well known. Core 12 may be made of othersuitable materials. Outer coating 14 preferably is a PVC plastisol, butmay be made of other suitable materials such as polyurethane.

In accordance with the present invention, coating 14 includesmicrospheres 16 (shown as “X”s in FIG. 1) dispersed throughout thecoating, with each microsphere 16 comprising a polymer shell thatencapsulates a small amount of a hydrocarbon gas (also called “polymermicrospheres” herein). Each polymer microsphere 16 thus features a smallamount of a hydrocarbon gas encapsulated in a gastight thermoplastic(polymer) shell. Examples of suitable gas filled microspheres withpolymer shells suitable for use in the present invention are those soldunder the product name EXPANCEL (type DE) by Expancel Inc., of Duluth,Ga., a division of AKZO NOBEL.

During manufacture of fly line 10 of the present invention, microspheres16 are added to the PVC plastisol to produce outer coating 14. Thepolymer microspheres are heated, causing the thermoplastic shell of eachsphere to soften and the pressure of the gas inside the shell toincrease. As the shells soften and the pressure within each shellincreases, the polymer microspheres dramatically expand which in turndecrease their density. Although not preferred, unexpanded polymermicrospheres may be employed.

Microspheres 16 are added to the plastisol preferably at a concentrationof between 1 and 10% by weight based on the total weight of theplastisol. The added polymer microspheres should be of very smallparticle size, for example, particle sizes smaller than 55 microns. Theproduct EXPANCEL 091 DE 40 d30 has an average particle size of 35 to 55microns and a true density of 0.03 grams per cubic centimeter, and thusis well suited for use in the present invention.

When polymer microspheres 16 are included within the fly line's coating14, the overall floatability of the fly line is substantially increased.As further described below, the inclusion of polymer microspheres 16 incoating 14 enables for the manufacture of fly lines that have a specificgravity of less than 0.85, as well as fly lines with a specific gravityof less than 0.80. Fly line 10 may be manufactured using the well knownvertical pulltrusion process. Other processes may be utilized, such asthe known horizontal extrusion.

During manufacture, the core of the line is pulled through an open bathcontaining a liquid adhesive that bonds the coating to the core. Theadhesion of the coating to the core is important and directly affectsthe durability of the line. A poor bond between the coating and the corewill cause the coating of the line to crack prematurely. From theadhesive bath the line passes through a primer oven to cure theadhesive. The adhesive coated core then passes through an open bathlocated under the cure oven that contains the liquid PVC plastisol thatincludes various additives such as silicone and microspheres. Theplastisol adheres to the core and then goes through a computercontrolled variable oriface die that forms the taper and scrapes off theexcess plastisol. The excess plastisol runs back into the bath. Once theplastisol is applied to the core and the taper is formed, the line goesthrough the cure oven to cure the plastisol so that the coating is nolonger a liquid but, rather, a flexible solid. From the oven, thefinished line is wound in a skein ready for inspection and packaging.

FIG. 2 schematically illustrate a more typical fly line in accordancewith the present invention, containing core 12 and outer coating 14,which contains the polymer microspheres 16 (microspheres not shown inFIG. 2).

U.S. Pat. No. 6,321,483, mentioned above, and which is incorporated byreference herein, teaches the addition of glass microspheres to theplastisol of a fly line's outer coating to impart floatability to theline. In that patent, G18/500 glass microspheres, manufactured byMinnesota Mining and Manufacturing Co., which have an average particlesize of 30 microns and a true density of 0.18 grams per cubiccentimeter, are used to produce fly lines having improved floatabilityas compared to previously manufactured fly lines. However, glassmicrospheres have their limitations and do not, by themselves, enablethe manufacture of practical fly lines that have specific gravities of0.80 and lower.

For example, in order to manufacture a fly line whose specific gravityis less than 0.80 using glass microspheres, a high concentration ofglass microspheres (e.g., whose total density is 0.18 grams per cubiccentimeter) must be added to the coating formulation. Suchconcentration, however, would result in a substantial increase in theviscosity of the coating formulation and would also result in asubstantial reduction in the formulation's durability, two unacceptablecharacteristics. In particular, a PVC plastisol with a substantiallyincreased viscosity would be detrimental to the manufacturing process,and the integrity of the coating would be compromised due to itsreduction in durability. Hence, fly lines with specific gravities ofless than 0.80 using glass microspheres are not manufactured.

In accordance with the present invention, the addition of polymermicrospheres (e.g., having a total density of 0.03 grams per cubiccentimeter), as discussed above, to the plastisol to produce the flyline's outer coating enables the manufacture of fly lines with specificgravities of less than 0.80 without the above-mentioned detrimentalaffects that result from using glass microspheres. One sixth theconcentration (volume) of polymer microspheres are needed, as comparedto the concentration of glass microspheres needed, to achieve these lowspecific gravities. Viscosity and durability of the plastisol are notmeaningfully affected by the addition of the polymer microspheres at therequired concentrations.

The following test data compares a fly line with an outer coating havingpolymer microspheres made in accordance with the present invention to afly line with an outer coating having glass microspheres. Duringtesting, the Expancel 091DE polymer microspheres were used as thepolymer microspheres 16, and 3M's G18/500 glass microspheres were usedin the other fly lines. Based on 7000 gram batches of uncured PVCplastisol fly line coating, the plastisol manufactured in accordancewith the present invention had 161 grams (2.3% by weight) of the polymermicrospheres to produce a coating having a specific gravity of 0.69.However, greater than 900 grams (11% by weight) of glass microsphereswere required to produce a coating with the same specific gravity. Thus,75% less polymer microspheres were required to achieve the same specificgravity as the glass microspheres.

Moreover, for the plastisol batches described above, the viscosity ofthe polymer microspheres plastisol batch was 93,760 Centistokes at 2.5RPM, whereas the glass microspheres plastisol batch had a viscosity of173,800 Centistokes at 2.5 RPM. The viscosities of both plastisolbatches were measured using a Brookfield Model RTV Viscometer. As iswell known in the art, plastisol batches whose viscosity is greater than100,000 Centistokes at 2.5 RPM result in serious manufacturingdifficulties using the vertical pulltrusion manufacturing process and,thus, plastisol viscosities of less than 100,000 are used.

In addition to producing a coating formulation with a desirableviscosity and a desirable, non-reduced durability, the use of polymermicrospheres advantageously provides for a reduced stiffness coating. Asmentioned above, substantially fewer polymer microspheres are needed toproduce a desired specific gravity, as compared to the amount of glassmicrospheres needed. With fewer polymer microspheres, a more supple flyline is produced. As is well known, a supple line handles better incolder conditions and causes less “drag” on the fly, i.e., permits thefly to float freely, as if unattached to a line (which makes it moreconvincing to fish). Still further, polymer microspheres are moreflexible than glass microspheres, resulting in lower stiffness. As iswell known, less stiffness results in a fly line with less memory, whichis the tendency for the line to remain coiled when removed from a flyreel. Reduced stiffness also is particularly desirable during coldwaterfly fishing.

As discussed above, the use of polymer microspheres in the outer coatingformulation improves floatability by producing fly lines with specificgravities of less than 0.80. Improved floatability has been seen in bothlaboratory and field testing as a result of the inclusion of expandedand unexpanded polymer microspheres into the fly line coating. Fly lineswith floating tips with specific gravities of less than 0.60 have beenachieved. Specific gravities were measured using a Pyknometermanufactured by Thomas Scientific. For fly lines with specific gravitiesof 0.80 and higher, the known MAD (Methyl Alcohol Density) Test may beused, where the coating is suspended in methyl alcohol. As is known, thespecific gravity of the line is ascertained by multiplying the specificgravity of methyl alcohol (0.7922) by the weight of the line in airwhich is divided by the difference between the weight of the line in airand the weight of the line in methyl alcohol. For fly lines withspecific gravities of between 0.66 and 0.80, specific gravity may beascertained by weighing the line in hexane, whose specific gravity is0.66, rather than methyl alcohol using the same procedures noted above.

Referring now to FIGS. 3 and 4 of the drawings, a fly line in accordancewith a second embodiment of the invention is schematically shown. FIG. 3is a perspective schematic illustration of fly line 20 shown withvarious layers partially removed, and FIG. 4 is a cross-sectional viewof fly line 20. Fly line 20 has a core 22, an inner coating 24 disposedover core 22, and an outer coating 26 disposed over inner coating 24.

Like core 12 in the first embodiment, core 22 is made of one or morefilaments, preferably a nylon monofilament or a nylon braidedmultifilament. Inner coating 24 (also called “first coating” or “firstinner coating”) preferably is a PVC plastisol. Outer coating 26 (alsocalled “second coating” or “second outer coating”) also preferably is aPVC plastisol.

In accordance with the present invention, the PVC plastisol of innercoating 24 includes polymer microspheres 28 (shown as “X”s in FIGS. 3and 4)), that is, the previously described microspheres with hydrocarbonencapsulated in a gastight thermoplastic shell. The outer coating 26includes glass microspheres (shown as “O”s in FIGS. 3 and 4), such asthose described in U.S. Pat. No. 6,321,483, mentioned above.

During manufacture of fly line 20 of the present invention, innercoating 24 and outer coating 26 are fully cured simultaneously,resulting in a fusion interface 32 between the two coatings. As a resultof the two coatings fusing together during curing, becoming an integralcoating, enhanced durability and structural integrity are achieved.

In a particular embodiment, fly line 20 of the present invention ismanufactured in accordance with the below-described novel process. Withreference to FIG. 5 of the drawings, the various steps are carried out.(1) Core 100 is pulled through an open bath 102 containing a liquidadhesive 104 that bonds the coating to the core. (2) The line thenpasses through a primer oven 106 to cure the adhesive. (3) As the lineexits the bottom of primer oven 106, it passes through a bath 108containing liquid PVC plastisol that contains additives, includingpolymer microspheres and silicone. (4) After the PVC plastisol isapplied to the line, the line goes through a fixed oriface die 10 thatpreferably forms an inner coating having a non-varying thickness of0.003 inches. The line then goes back through primer oven 106 and ispartially cured. During this curing, the primer oven has a temperatureof about 220 degrees Fahrenheit, which is lower than the fully curetemperature of PVC plastisol (about 380 degrees Fahrenheit). At thispoint, the inner coating is sufficiently cured to retain its shape(i.e., diameter). (5) The line, now with a partially cured PVC innercoating, goes from the primer oven through an outer coating PVCplastisol bath 112. (6) After applying the outer coating, the line goesthrough a variable oriface die 114. The variable orifice die, preferablycontrolled by a computer 116, forms a tapered outer coating. (7) Theline, now having both inner and outer coatings, is fully cured in a cureoven 118. The line is formed into a skein 120.

In accordance with the present invention, the inner coating is onlypartially cured at the time the outer coating is applied. As mentionedabove, the partially cured inner coating retains its shape, although itis not fully cured. Since the inner coating is not fully cured, theinner and outer coatings are fused together in the cure oven, whichfully cures both coatings. As mentioned above, fusion of the two layersincreases the line's durability.

FIG. 6 is a photographic image, 50× magnification, of a longitudinalcross section of fly line 20, showing the fly line's core 22, innercoating 24, outer coating 26 and the fusion interface 32. Although notpreferred, it is possible to fully cure each layer separately, in twoseparate operations, but the layers will not fuse as well.

A fly line in accordance with a third embodiment of the invention isschematically shown in FIGS. 7 and 8. FIG. 7 is a perspective schematicillustration of a fly line 40 shown with various layers partiallyremoved, and FIG. 8 is a cross-sectional view of fly line 40. Like thesecond embodiment discussed above, fly line 40 has a core 42 and aninner coating 44 containing polymer microspheres 48 (shown as single“X”s in FIGS. 7 and 8). However, fly line 40 of the third embodimentdiffers from the second embodiment in that outer coating 46 containspolymer microspheres (shown as “XX”s in FIGS. 7 and 8).

During manufacture of fly line 40 of the present invention, innercoating 44 and outer coating 46 are fully cured over core 42simultaneously, resulting in a fusion interface 52 between the twocoatings. However, the two coatings may be disposed and fully curedseparately. The process described above with reference to FIG. 5preferably is utilized to produce fly line 40.

FIG. 9 shows an exemplary fly line in accordance with a fourthembodiment of the present invention. As shown, fly line 60 comprisesmultiple coatings and includes a floatation tip 62, a body 64 and arunning line 66. Fly line 60 includes a core 70, which preferably isnylon monofilament or nylon multifilament and preferably has a diameterof between 0.018 inches an 0.028 inches, generally depending on the sizeof the line. Both floatation tip 62 and running line 66 preferably haveoverall diameters between 0.035 inches and 0.045 inches, and body 64 hasa preferred diameter of between 0.045 inches and 0.115 inches, generallydepending on the size and taper of the line. Fly line 60 includes aninner coating 72 that extends through the floatation tip 62, body 64 andrunning line 66. Inner coating 72 preferably has a constant thickness ofaround 0.003 inches and is 0.006 inches larger than the core sizeindependent of line size, taper or core diameter.

In accordance with the present invention, fly line 60 includes coatingscomprised of three different types of PVC plastisol mixtures (batches)(for convenience, referred to herein as plastisol mixtures or batches“A”, “B” and “C”). Each of the plastisol mixtures “A”, “B” and “C”preferably has a Shore A hardness of 80 durometer.

Batch “A” is used as the outer coating 74, which extends along body 64and running line 66. Batch “B” is used as the outer coating 76, whichextends along floating (or “floatation”) tip 62. Batch “C” is used asthe inner coating 72, which extends along floatation tip 62, body 64 andrunning line 66.

Batches “B” and “C” incorporate the above-described polymer microspheresand preferably have the same specific gravity of between 0.70 and 0.71.Preferably, batch “B” has a viscosity of 45520 centistokes and batch “C”has a viscosity of 12320 centistokes. Batch “A” incorporates theabove-mentioned glass microspheres and preferably has a specific gravityof between 0.87 and 0.88, with a preferred viscosity of around 26080centistokes. In the illustrative line shown in FIG. 9, running line 66has a specific gravity of 0.813, body 64 has a specific gravity of0.832, and floating tip 62 has a specific gravity of 0.668, thusproviding an overall specific gravity of line 60 of 0.818.

Below are tables showing the composition of batches “A”, “B” and “C” inthe illustrative example, where 3M's G/18 microspheres are used as theglass microspheres and the Expancel 091 DE product mentioned above isused as the polymer microspheres.

Plastisol Batch “A” Density 0.87-0.88 Viscosity at 5 RPM: 26000-30000Ingredient Amount % PVC Plastisol 7500 g 89.2 Silicone 225 g 2.6Fluorescent Green Dye 112.2 g 1.3 Glass Microspheres 540 g 6.45

Plastisol Batch “B” Density 0.70-0.71 Viscosity at 5 RPM: 45000-50000Ingredient Amount % PVC Plastisol 7000 g 93.8 Silicone 35 g 2.8Fluorescent Green Dye 105 g 1.4 Polymer Microspheres 143.5 1.9

Plastisol Batch “C” Density 0.70-0.71 Viscosity at 5 RPM: 10000-15000Ingredient Amount % PVC Plastisol 7000 g 93.8 Silicone 35 g 2.8Fluorescent Green Dye 105 g 1.4 Polymer Microspheres 143.5 1.9

In the exemplary batches shown in the tables above, batch “A” includesPVC Plastisol, 80 Durometer, 39000 Centistokes viscosity equivalent toLakeside industries JX-288, and liquid silicone with a 100,000Centistokes viscosity equivalent to Dow Corning DC 200. For batch “B”,the PVC plastisol and silicone components are the same as in batch “A.”Batch “C” includes PVC plastisol, 80 Durometer, 7200 Centistokesviscosity and the liquid silicone described in batch “A.”

As described above, outer coating 74 is made using glass microspheresand thus results in a higher specific gravity of both body 64 andrunning line 66 as compared to the specific gravity of floating tip 62,which incorporate polymer microspheres in its outer coating 76. However,body 64 and running line 66 includes the coatings as described so as toresult in both increased smoothness and increased durability. As forfloating tip 62, the use of inner and outer coatings that includepolymer microspheres provides for a resultant specific gravity of 0.668,which is significantly lower that that of either body 64 or running line66. For illustrative purposes, if plastisol batch “B” were made fromglass microspheres to produce an outer coating with a specific gravityof between 0.70 and 0.71, greater than 900 grams of glass microspheres(11%) would need needed. The resultant plastisol, however, would have aan unacceptable viscosity at 5 RPM of over 200,000 Centistokes.

In each of the embodiments described herein, the fly line coating orcoatings must have a specific gravity that is low enough to offset thespecific gravity of the core. Nylon monofilament cores are solid andhave an effective specific gravity of 1.00 to 1.15. Nylon braidedmultifilament cores consist of multiple small diameter nylon strandsbraided around a hollow core and have an effective specific gravity ofapproximately 0.90. The individual strands in a Nylon braidedmultifilament core have a specific gravity of 1.00 to 1.15, but sincethe core is hollow and traps air when the coating is applied, thetrapped air reduces the line's overall specific gravity.

Lines having a single coating over a hollow multifilament core will tendto wick water into the hollow core during use, thus increasing theline's specific gravity which in turn causes the line's tip to sink.However, lines manufactured in accordance with the present inventionhave specific gravities sufficiently low to offset the affect of waterbeing wicked up into the core, thus preventing the line's tip fromsinking as water is wicked up during use.

The coatings described above that employ polymer microspheres not onlydecrease the specific gravity of the fly line, they decrease specificgravity without increasing the fly line's cross sectional area. Forconventional fly lines (e.g., having glass microspheres in the coating),the line's specific gravity can be reduced by increasing the volume ofglass microspheres to the PVC plastisol, as previously discussed, or byincreasing the cross sectional area of the coating. Neither is desiredor practical. When cross sectional area is increased, air resistancealso is increased which in turn results in a loss of distance whencasting.

The multiple coating fly lines discussed above in the second, third andfourth embodiments provide further advantageous features. In addition toproviding fly lines that float higher, multiple coats over the coreproduce a smoother outer surface resulting in a line that is smooth,slick and having a lower coefficient of friction as compared to lineshaving only a single coating. A lower coefficient of friction results inless friction as the line goes through the rod guides which in turnresults in longer casts.

The core of fly lines generally have rough surfaces, especially braidednylon multifilament cores and braided nylon monofilament cores. Lineshaving only a single coating have higher coefficients of friction, ascompared to those with multiple coatings, since the rough surface of thecore transfers through the thin cross sections of the line to create arelatively rough surface. The inner coatings described herein fills inthe voids in the core and produces a smooth level surface on the coreresulting in a smooth surface on the outer coating.

A fly line with an outer coating having a higher specific gravity (e.g.,0.87) has a smoother surface as compared to a line with an outer coatingwith a lower specific gravity (e.g., 0.84) due to the use of fewermicrospheres in the higher specific gravity line. As the concentrationof microspheres increases, more microspheres protrude through thecoating's surface thus resulting in a rougher line. By employing aninner coating, the outer coating becomes smoother since the innercoating provides a smooth substrate for the outer coating. A smootherouter coating can also be achieved by increasing the durometer of theouter coating but doing so also increases its hardness and itsresistance to bending and thus reduces the suppleness of the line. As iswell known, a smoother and slicker (i.e., lower coefficient of friction)line can be cast further. FIGS. 10 and 11 illustrate the slickness of asingle coat line and a double coat line, respectively, manufactured asherein described.

Slickness (coefficient of friction) is a comparative test, and testingmay be achieved as follows: Using an Instron Model 4443 Tensile Testerwith a 10 Kilogram load cell, a section of fly line 0.050 inches indiameter with a 0.123 pound weight attached to one end is drawn over a 7inch diameter chrome plated wheel at a rate of 10 inches per minute bythe Instron. The line has a surface contact length of 22 inches to thewheel. As the line is drawn across the wheel, the Instron measures theamount of force required to pull the line over the wheel. A slick linerequires less force to pull over the wheel as compared to a rough line.Four tests were conducted on each line and are identified in FIGS. 10and 11 as specimens 1-4. The numerical value identified adjacent to eachspecimen number is the force in pounds required to pull the line overthe wheel, the mean being the average of the four tests. To determinethe force, the 0.123 weight is subtracted from the mean. For example,0.335−0.123=0.212 pounds for the single coat line (FIG. 10) and0.290−0.123=0.167 pounds for the double coat line (FIG. 11).Effectively, the double coat line has a coefficient of friction that is21% less than the single coat line.

The centering of the core in the fly line coating also is important tothe durability and structural integrity of the line. If the core is notcentrally located in the cross section of the line, the coating will bethin on one side of the core and thick on the other side of the core.The side where the coating is thin will be deteriorated by the frictioncreated by the rod guides prematurely due to the reduced cross sectionof the coating. The roundness of the core affects centering. If the coreis not round, centering the core within the cross section of the coatingin manufacturing is difficult. The inner coating enhances the roundnessof the core thus making centering easier and subsequently increasingdurability. Moreover, due to the existence of the outer coating, theinner coating can be variable in thickness without degrading the qualityof the fly line.

The present invention has been described in accordance with particularembodiments as described herein, as well as variations thereof However,it is intended that the appended claims be interpreted as including theembodiments described herein, the alternatives mentioned above, and allequivalents thereto.

1. A method of manufacturing a fishing line, comprising the steps of:providing a core; disposing a first coating around the core, the firstcoating having a plurality of polymer microspheres; and disposing asecond coating around the first coating, the step of disposing a firstcoating around the core including partially curing the first coating toprovide a partially cured first coating disposed around the core; andthe step of disposing a second coating around the first coating beingcarried out by disposing the second coating around the partially curedfirst coating.
 2. The method of claim 1, wherein the step of disposing afirst coating around the core disposes the first coating in apredetermined shape around the core; and curing the first coating iscarried out to partially cure the first coating sufficiently to providea not-fully cured first coating adapted to maintain the predeterminedshape during carrying out of the step of disposing the second coatingaround the first coating.
 3. The method of claim 1, comprising, afterdisposing the second coating around the partially cured first coating,heating the fishing line to a temperature sufficient to fully cure thefirst and second coatings thereby producing a fused interface betweenthe first and second coatings.
 4. A method of manufacturing a fishingline, comprising the steps of: providing a core; disposing a firstcoating around the core, the first coating having a plurality of polymermicrospheres; and disposing a second coating around the first coating,the step of disposing a first coating around the core being carried outby disposing the first coating around first and second portions of thecore; and the step of disposing the second coating around the firstcoating being carried out by disposing the second coating around thatportion of the first coating that is disposed around the first coreportion; the method further comprising disposing a third coating aroundthat portion of the first coating that is disposed around the secondcore portion, the second and third coatings having microspheres made ofdifferent materials, and the second coating has a plurality of polymermicrospheres, and the third coating includes a plurality of glassmicrospheres.
 5. A method of manufacturing a fishing line, comprisingthe steps of: providing a core; disposing a first coating around thecore, the first coating having a plurality of polymer microspheres; anddisposing a second coating around the first coating, the step ofdisposing a first coating around the core being carried out by disposingthe first coating around first and second portions of the core; and thestep of disposing the second coating around the first coating beingcarried out by disposing the second coating around that portion of thefirst coating that is disposed around the first core portion; the methodfurther comprising disposing a third coating around that portion of thefirst coating that is disposed around the second core portion, andadding a plurality of polymer microspheres to only one of the second andthird coatings, and a viscosity of said one of the second and thirdcoatings having the added plurality of polymer microspheres is differentfrom a viscosity of the first coating having the plurality of polymermicrospheres.
 6. The method of claim 5, comprising adding a plurality ofglass microsphere to the other of said one of the second and thirdcoatings.